We have developed methodology to detect individual T cell reactivity to cellular antigens and demonstrated the specificity and utility of this system. This technology is being applied to the study of human T cells obtained from patients with metastatic renal cell carcinoma. We are also engaged in a cooperative research venture with Dr. Peter Cohen of the Surgery Branch, NCI to detect proliferation of T cells from patients with renal cell carcinoma following exposure to tumor pulsed antigen presenting cells. We are studying the proliferation of these cells by 3H thymidine proliferation assay. We have also perfected a technique for the rapid purification of CD4 T cells from human lymphoid compartments for use in these experiments. The laboratory is also engaged in the flow cytometric analysis of peripheral blood lymphocytes from patients with metastatic cancer undergoing experimental therapy with interleukin-6. We have identified some activation markers in peripheral blood T cell compartment caused by the IL-6 administration. This work is ongoing. The significance of these projects is the detection of individual T cell reactivity to tumors. The production of T cell populations with specific antitumor reactivity would provide very useful information in understanding the nature of the immune response to cancer in patients with metastatic or localized disease. Such cells could also be used in therapy trials.